Saber-toothed cats are fossiliferous rock stars. The long, curved fangs jutting from their upper jaws have transfixed experts and the public alike since their discovery in the 19th century. You might even say that they’re on point. And after decades of investigation and debate, the paleontological consensus is that these powerful cats deployed their fangs against the soft tissues of mammals like ancient camel and bison. The cats avoided biting into bone, instead shearing through muscle, blood vessels, and other critical systems that would inflict terrible trauma on their prey.
The plan of attack makes sense. While certainly impressive, the blade-like canines of Smilodon and other saber-toothed cats were undercut by a structural weakness. Side-to-side bending and similar stresses would be likely to break the teeth. A specimen of Smilodon populator at the American Museum of Natural History is one such cat who had to cope with such a break. In general, the hypothesis goes, the cats avoided jamming their teeth anywhere near the skeleton and instead focused on ripping out chunks of soft tissue. The wait, strike, and wait tactics of great white sharks probably have more in common with saber-toothed cats than the strategies of modern tigers and jaguars.
But there were times when Smilodon were not so shy about biting into bone. Pathological skulls, with wounds made by other Smilodon, tell the tale.
At the La Brea asphalt seeps in Los Angeles, there’s a Smilodon fatalis skull with a particularly gnarly injury. It’s a deep and likely-fatal gash in the roof of one cat's skull, and it appears that the weapon used to inflict the damage was the tooth of another Smilodon. It stood for a long time as something of an outlier, a rare example of prehistoric violence. Now paleontologist Nicolás Chimento and colleagues have added another two Smilodon populator skulls to the list. While the injuries to the skulls could have been caused by kicking prey, the researchers write, the most likely suspects are other Smilodon.
Both skulls, found at different places in Argentina, are new finds that show similar pathologies. Each has a puncture at the skull suture between the nasal and frontal bones, a chasm driving down into the face. They also resemble injuries seen on the skull of a different saber-toothed cat, Machairodus. What’s more, when Chimento and colleagues placed a Smilodon fang into their fossil wounds, the tooth looked to be a close fit.
Perhaps we’ve been underestimating the ancient abilities of Smilodon and other saber-tooths. A significant number of fossils belonging to saber-tooths called nimravids – close to cats, but not true cats – show bite marks on their skulls. One famous specimen even preserves a nimravid who bit into the arm of another and got stuck. Between these fossils, the Machairodus specimen, and the several Smilodon, it seems these cats often went for the face when confronting each other.
Whether these cats were as brave with their prey is a different story. A fight to eat and a fight between competitors are two different things. Still, the skull of a different animal may offer a clue. A glyptodont skull at the AMNH, on the other side of the wall from the injured Smilodon, shows two oval holes in the top that could have been made by a saber-toothed cat. A big jaguar is also a possibility, but perhaps a re-examination of this fossil will offer new clues. The answer isn’t clear yet. All the same, perhaps saber-toothed cats weren’t as wary of all bones as was suspected. A vertebra or limb bone has a lot of compact tissue and may be more likely to injure a saber-toothed cat’s tooth, but skull bones are often thinner and spongier. Perhaps, in a pinch, a skull bite could work just as well as a neck chomp.